US6487005B2 - Optical fiber transmission system with chromatic dispersion compensation - Google Patents

Optical fiber transmission system with chromatic dispersion compensation Download PDF

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US6487005B2
US6487005B2 US09/903,121 US90312101A US6487005B2 US 6487005 B2 US6487005 B2 US 6487005B2 US 90312101 A US90312101 A US 90312101A US 6487005 B2 US6487005 B2 US 6487005B2
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segments
dispersion
chromatic dispersion
optical line
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Thierry Georges
Daniel Le Guen
Francois Favre
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Orange SA
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France Telecom SA
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    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04BTRANSMISSION
    • H04B10/00Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/25Arrangements specific to fibre transmission
    • H04B10/2507Arrangements specific to fibre transmission for the reduction or elimination of distortion or dispersion
    • H04B10/2513Arrangements specific to fibre transmission for the reduction or elimination of distortion or dispersion due to chromatic dispersion
    • H04B10/2525Arrangements specific to fibre transmission for the reduction or elimination of distortion or dispersion due to chromatic dispersion using dispersion-compensating fibres
    • H04B10/25253Arrangements specific to fibre transmission for the reduction or elimination of distortion or dispersion due to chromatic dispersion using dispersion-compensating fibres with dispersion management, i.e. using a combination of different kind of fibres in the transmission system
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01SDEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S3/00Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
    • H01S3/05Construction or shape of optical resonators; Accommodation of active medium therein; Shape of active medium
    • H01S3/06Construction or shape of active medium
    • H01S3/063Waveguide lasers, i.e. whereby the dimensions of the waveguide are of the order of the light wavelength
    • H01S3/067Fibre lasers
    • H01S3/06754Fibre amplifiers
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01SDEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S3/00Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
    • H01S3/10Controlling the intensity, frequency, phase, polarisation or direction of the emitted radiation, e.g. switching, gating, modulating or demodulating
    • H01S3/10007Controlling the intensity, frequency, phase, polarisation or direction of the emitted radiation, e.g. switching, gating, modulating or demodulating in optical amplifiers
    • H01S3/1001Controlling the intensity, frequency, phase, polarisation or direction of the emitted radiation, e.g. switching, gating, modulating or demodulating in optical amplifiers by controlling the optical pumping
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01SDEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S3/00Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
    • H01S3/30Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range using scattering effects, e.g. stimulated Brillouin or Raman effects
    • H01S3/302Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range using scattering effects, e.g. stimulated Brillouin or Raman effects in an optical fibre
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01SDEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S3/00Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
    • H01S3/09Processes or apparatus for excitation, e.g. pumping
    • H01S3/091Processes or apparatus for excitation, e.g. pumping using optical pumping
    • H01S3/094Processes or apparatus for excitation, e.g. pumping using optical pumping by coherent light
    • H01S3/094042Processes or apparatus for excitation, e.g. pumping using optical pumping by coherent light of a fibre laser
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01SDEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S3/00Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
    • H01S3/09Processes or apparatus for excitation, e.g. pumping
    • H01S3/091Processes or apparatus for excitation, e.g. pumping using optical pumping
    • H01S3/094Processes or apparatus for excitation, e.g. pumping using optical pumping by coherent light
    • H01S3/094096Multi-wavelength pumping
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01SDEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S3/00Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
    • H01S3/09Processes or apparatus for excitation, e.g. pumping
    • H01S3/091Processes or apparatus for excitation, e.g. pumping using optical pumping
    • H01S3/094Processes or apparatus for excitation, e.g. pumping using optical pumping by coherent light
    • H01S3/0941Processes or apparatus for excitation, e.g. pumping using optical pumping by coherent light of a laser diode
    • H01S3/09415Processes or apparatus for excitation, e.g. pumping using optical pumping by coherent light of a laser diode the pumping beam being parallel to the lasing mode of the pumped medium, e.g. end-pumping
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04BTRANSMISSION
    • H04B2210/00Indexing scheme relating to optical transmission systems
    • H04B2210/003Devices including multiple stages, e.g., multi-stage optical amplifiers or dispersion compensators

Definitions

  • the present invention relates to optical fiber transmission systems.
  • an advantageous application of the invention lies in long-distance transmission systems, and in particular in transoceanic transmission systems which need to be capable of carrying information over distances in excess of 5000 kilometers (km).
  • RZ return to zero
  • local chromatic dispersion serves to reduce non-linear interaction phenomena between channels (four-wave mixing), while compensating the chromatic dispersion of the fibers makes it possible to obtain mean chromatic dispersion that is small and consequently makes it possible to minimize phenomena of pulse spreading.
  • the chromatic dispersion slope can be reduced in various ways and in particular either by using small-slope fibers or by using fibers having slopes of opposite signs, or by demultiplexing the channels and compensating chromatic dispersion individually in each channel.
  • the object of the invention is to mitigate the drawbacks of prior techniques and to propose a long-distance transmission system enabling high data rates with dense multiplexing and with a large passband.
  • British patent GB 2 299 473 discloses a long-distance optical transmission system comprising pulse emitter and receiver means and an optical line which extends between said emitter and receiver means and which comprises alternating segments of dispersive fibers having chromatic dispersion of opposite signs, and also a plurality of amplifiers, said optical lines including one pair of dispersive fiber segments having chromatic dispersion of opposite signs between successive amplifiers.
  • the invention provides a long-distance optical transmission system comprising pulse emitter and receiver means and an optical line which extends between said emitter and receiver means and which comprises alternating segments of dispersive fibers having chromatic dispersion of opposite signs, and also having a plurality of amplifiers, said optical line comprising at least one pair of dispersive fiber segments having chromatic dispersion of opposite signs between successive amplifiers, the system being characterized in that said optical line comprises a plurality of such pairs between successive amplifiers, and in that the cumulative dispersion C over the majority of the segments of the optical line satisfies the relationship.
  • system proposed by the invention advantageously includes the various following characteristics taken singly or in any feasible combination:
  • the chromatic dispersion of the segments of anomalous dispersion fiber is about 17 ps/nm/km at a wavelength of 1550 nm;
  • the chromatic dispersion of segments of normal dispersion fiber is about ⁇ 85 ps/nm/km;
  • the optical line has three pairs of segments of dispersive fibers having chromatic dispersion of opposite signs, between successive amplifiers;
  • a segment of anomalous dispersion fiber extends over a distance of about 10 km and a segment of normal dispersion fiber extends over a distance of about 2 km;
  • the chromatic dispersion of the segments of normal dispersion fiber is about ⁇ 17 ps/nm/km;
  • the optical line has two pairs of segments of dispersive fibers having chromatic dispersion of opposite signs between successive amplifiers;
  • a segment of fiber extends over a distance of about 10 km.
  • FIG. 1 is a diagram of a transmission system constituting a possible embodiment of the invention
  • FIG. 2 is a graph plotting maps of cumulative dispersion in a prior art transmission system and in a transmission system constituting a possible embodiment of the invention.
  • the system shown in FIG. 1 has emitter means 1 , receiver means 2 , and an optical transmission line 3 which extends between said emitter and receiver means 1 and 2 .
  • the emitter means 1 generate an optical signal constituted by a succession of RZ pulses.
  • the receiver means demodulate the signal after it has been transmitted by the line 3 .
  • This optical transmission line 3 includes a plurality of amplifiers 4 which are regularly distributed along its length.
  • the line has a plurality of fiber segments 3 a of anomalous dispersion alternating with fiber segments 3 b of normal dispersion.
  • is the half-height spectral width of the pulses (expressed in THz) and where C is the cumulative dispersion expressed in ps/nm.
  • the cumulative dispersion satisfies:
  • the cumulative dispersion is advantageously less than 150 ps/nm; for a channel data rate of 40 Gbit/s, the cumulative dispersion is advantageously less than 30 ps/nm.
  • the cumulative dispersion of the fiber segments also advantageously satisfies the relationship:
  • This condition makes it possible to reduce four-wave mixing and to reduce interaction between successive pulses.
  • anomalous fiber segments are advantageously selected to have chromatic dispersion greater than 8 ps/nm/km while the normal fiber segments are selected to have chromatic dispersion whose absolute value is greater than 8 ps/nm/km.
  • FIG. 2 is a map of the cumulative dispersion C 1 (z) (where z is distance) in a transmission system satisfying relationship R and having a single pair of fiber segments between successive amplifiers 4 .
  • the second dispersion map makes it possible to use narrower pulses which interact less and which have smaller cross phase modulation effects than when using the first dispersion map.
  • the anomalous fiber segments 3 a are advantageously constituted by single-mode fibers (SMF) of the kind used in standard manner in telecommunications.
  • SMF single-mode fibers
  • SMF fibers are very dispersive.
  • the normal fiber segments 3 b are advantageously chromatic dispersion compensating fibers—referred to by the person skilled in the art as dispersion compensating fibers (DCF)—or reverse dispersion fibers (RDF), in which chromatic dispersion is substantially opposite to that of SMF fibers.
  • DCF dispersion compensating fibers
  • RDF reverse dispersion fibers
  • the distance between successive amplifiers 4 preferably lies in the range 35 km to 60 km.
  • the power level output by the amplifiers 4 is selected to be sufficient to enable a satisfactory signal-to-noise ratio to be achieved with low jitter.
  • the characteristics of the means 1 which constitute the emitter source are defined by the chromatic dispersion map of the transmission line 3 and by the inline power of each channel. They are selected to obtain an operating point that is stable, enabling small variations in spectrum width to be accommodated during propagation.
  • the dispersion at the input to the receiver means 2 is optimized so as to minimize jitter and so as to re-time the signal.
  • a system of the type described above can be used to transmit a multiplex of N ⁇ 20 Gbit/s (where N is an integer greater than or equal to 1, and can be as great as 40 or even more) over a transoceanic distance (>5000 km), together with line fibers constituted by standard fiber (SMF) which presents anomalous chromatic dispersion of about 17 ps/nm/km at a wavelength of 1550 nm, and a chromatic dispersion compensating fiber (DCF) which presents normal chromatic dispersion of about ⁇ 85 ps/nm/km.
  • SMF standard fiber
  • DCF chromatic dispersion compensating fiber
  • the transmission line 3 is made up of three SMF type fiber segments 3 a each having a length equal to 8 km and three DCF type fiber segments 3 b alternating between the SMF segments and each presenting a length of 1.59 km, which corresponds to a distance between successive amplifiers that is approximately equal to 29 km.
  • the mean chromatic dispersion is anomalous (slightly less than 0.1 ps/nm/km).
  • the power of the line amplifiers is ⁇ 1.5 decibels relative to 1 milliwatt (mW) per channel (dBm/channel) which amounts to 10.5 dBm for 16 channels).
  • Pulse duration is about 12 ps.
  • the initial chromatic dispersion (typically ⁇ 70 ps/nm) is optimized to obtain propagation that is stable.
  • the high chromatic dispersion value makes it possible for channels to be spaced apart by 0.8 nm, or even by 0.6 nm.
  • the segments 3 b are advantageously made using DCF type fibers having a chromatic dispersion slope of about ⁇ 0.26 ps/nm 2 /km.
  • the transmission wavelength bandwidth is then limited only by the flatness of the amplifiers and can therefore exceed 25 nm.
  • the transmission line 3 is constituted by two SMF type fiber segments 3 a each presenting a length of 8 km and two RDF type fiber segments 3 b alternating with the SMF segments and each presenting a length of 7.9 km, thus corresponding to a distance between successive amplifiers of approximately 32 km.
  • the mean chromatic dispersion is slightly less than 0.1 ps/nm/km.
  • the power of the line amplifiers is 2 dBm/channel (i.e. 10 dBm for 16 channels). Pulse duration is about 13 ps. Channel spacing can be 0.8 nm or even 0.6 nm because of the high value of the chromatic dispersion.
  • the RDF segments have a chromatic dispersion slope of about ⁇ 0.05 ps/nm 2 /km which completely compensates the chromatic dispersion slope of the SMF segment (0.053 ps/nm 2 /km). The total bandwidth is thus limited by the flatness of the amplifiers and can therefore exceed 25 nm.
  • a total data rate in excess of 40 ⁇ 20 Gbit/s can be transmitted over a transoceanic distance.

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  • Engineering & Computer Science (AREA)
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Abstract

A long-distance optical transmission system comprising pulse emitter and receiver means (1, 2) and an optical line (3) which extends between said emitter and receiver means (1, 2) and which comprises alternating segments (3 a , 3 b) of dispersive fibers having chromatic dispersion of opposite signs, and also having a plurality of amplifiers (4), the system being characterized in that the optical line (3) comprises a plurality of pairs of dispersive fiber segments (3 a , 3 b) having chromatic is dispersion of opposite signs between successive amplifiers (4), and in that the cumulative dispersion C over the majority of the segments of the optical line satisfies the relationship
(R)|C|Δν2 <0.3
where C is expressed in ps/nm and where Δν is the half-height spectral value of the pulses expressed in Thz.

Description

This application claims priority from PCT application PCT/FR00/00044, filed Jan. 11, 2000, which is based upon French national application 99/00184, filed Jan. 11, 1999.
The present invention relates to optical fiber transmission systems.
In particular, an advantageous application of the invention lies in long-distance transmission systems, and in particular in transoceanic transmission systems which need to be capable of carrying information over distances in excess of 5000 kilometers (km).
Numerous long-distance transmission systems have already been proposed which implement return to zero (RZ) modulation, i.e. modulation in the form of pulses of duration shorter than the bit time, and which comprise two segments of dispersive fiber between successive amplifiers (e.g. constituted by erbium-doped fibers) the segments having chromatic dispersion of opposite signs and compensating each other.
In such systems, local chromatic dispersion serves to reduce non-linear interaction phenomena between channels (four-wave mixing), while compensating the chromatic dispersion of the fibers makes it possible to obtain mean chromatic dispersion that is small and consequently makes it possible to minimize phenomena of pulse spreading.
The chromatic dispersion slope can be reduced in various ways and in particular either by using small-slope fibers or by using fibers having slopes of opposite signs, or by demultiplexing the channels and compensating chromatic dispersion individually in each channel.
For descriptions of optical transmission systems implementing chromatic dispersion compensation, reference can advantageously be made to the following publications:
[1] I. Morita, K. Tanaka, N. Edagawa, M. Suzuki, “40 Gbit/s single-channel soliton transmission over 10,200 km without active inline transmission control”, Post-deadline paper, p. 49, ECOC'98 (Madrid);
[2] N. Edagawa, I. Morita, M. Suzuki, S. Yamamoto, K. Tanaka, S. Akiba, “Long distance soliton WDM transmission using a dispersion-flattened fiber”, Post-deadline paper PD19, OFC'97 (Dallas);
[3] M. Suzuki, H. Kidorf, N. Edagawa, H. Taga, N. Takeda, K. Imai, I. Morita, S. Yamamoto, E. Shibano, T. Miyakawa, E. Nazuka, M. Ma, F. Kerfoot, R. Maybach, H. Adelmann, V. Arya, C. Chen, S. Evangelides, D. Gray, B. Pedersen, A. Puc, “170 Gbit/s transmission over 10,850 km using large core transmission fiber”, Post-deadline paper PD17, OFC'98 (San Jose);
[4] N. Edagawa, M. Suzuki, N. Takeda, K. Imai, S. Yamamoto, S. Akiba, “213 Gbit/s. (20×10.66) over 9000 km transmission experiment using dispersion-slope compensator”, Post-deadline paper PD13, OFC'98 (San Jose);
[5] M. Murakami, T. Matsuda, T. Imai, “Quarter Terabit (25×10 Gbit/s) over 9288 km WDM, transmission experiment using non-linear supported RZ pulse in higher order fiber dispersion managed line”, Post-deadline paper, p. 79, ECOC'98 (Madrid);
[6] D. Le Guen, A. O'Hare, S. Del Burgo, D. Grot, F. Favre, T. Georges, “Narrow band 640 Gbit/s soliton WDM transmission over 1200 km of standard fiber with 100 km-21 dB amplifier spans”, Post-deadline paper, p. 61, ECOC'98 (Madrid).
Nevertheless, the systems described in publications [1-5] have the drawback of not enabling high transmission rates to be achieved because of cross phase modulation phenomena between adjacent channels preventing multiplexing being sufficiently dense, i.e. a channel separation of less than 0.8 (nanometers) (nm) for 20 gigabits per second (Gbit/s) channels, of 1.8 nm for 40 Gbit/s channels, and of 0.4 nm at 10 Gbit/s (references [1] and [2]). The system of reference [6] allows multiplexing to be dense but over distances that are too short (2000 km) and limited by interaction.
To enable high data rates to be achieved over transoceanic distances, proposals have also been made for transmission systems implement soliton type modulation.
Systems of that type are described, for example, in the following publication:
M. Nakazawa et al., “16 Gbit/s WDM (20 Gbit/s×8 channels) soliton transmission over 10,000 km using inline synchronous modulation and optical filtering”, PD10-1, Optical Soliton Transmission Research Group—NTT Access Network Systems Laboratories—Tokai, Ibaraki-ken 319-11 Japan.
However, the technique proposed in the above article is very difficult to implement because of the precision required (better than 0.1 picoseconds per nanometer per kilometer (ps/nm/km)) concerning the value of chromatic dispersion in each of the fiber segments.
In addition, when using fibers with non-zero chromatic dispersion slope, that technique allows transmission on certain wavelengths only.
The object of the invention is to mitigate the drawbacks of prior techniques and to propose a long-distance transmission system enabling high data rates with dense multiplexing and with a large passband.
British patent GB 2 299 473 discloses a long-distance optical transmission system comprising pulse emitter and receiver means and an optical line which extends between said emitter and receiver means and which comprises alternating segments of dispersive fibers having chromatic dispersion of opposite signs, and also a plurality of amplifiers, said optical lines including one pair of dispersive fiber segments having chromatic dispersion of opposite signs between successive amplifiers.
The invention provides a long-distance optical transmission system comprising pulse emitter and receiver means and an optical line which extends between said emitter and receiver means and which comprises alternating segments of dispersive fibers having chromatic dispersion of opposite signs, and also having a plurality of amplifiers, said optical line comprising at least one pair of dispersive fiber segments having chromatic dispersion of opposite signs between successive amplifiers, the system being characterized in that said optical line comprises a plurality of such pairs between successive amplifiers, and in that the cumulative dispersion C over the majority of the segments of the optical line satisfies the relationship.
 |C|Δν2<0.3
where C is expressed in ps/nm and where Δν is the half-height spectral value of the pulses expressed in terahertz (THz)
In addition, the system proposed by the invention advantageously includes the various following characteristics taken singly or in any feasible combination:
the cumulative dispersion C of the segments of the optical line satisfies the relationship:
|C|Δν2<0.25
where C is expressed in ps/nm and where Δν is expressed in THz;
the cumulative dispersion C of the segments of the optical line satisfies the relationship:
0.03<|C|Δν2
where C is expressed in ps/nm and where Δν is expressed in THz;
the chromatic dispersion of the segments of anomalous dispersion fiber is about 17 ps/nm/km at a wavelength of 1550 nm;
the chromatic dispersion of segments of normal dispersion fiber is about −85 ps/nm/km;
the optical line has three pairs of segments of dispersive fibers having chromatic dispersion of opposite signs, between successive amplifiers;
a segment of anomalous dispersion fiber extends over a distance of about 10 km and a segment of normal dispersion fiber extends over a distance of about 2 km;
the chromatic dispersion of the segments of normal dispersion fiber is about −17 ps/nm/km;
the optical line has two pairs of segments of dispersive fibers having chromatic dispersion of opposite signs between successive amplifiers; and
a segment of fiber extends over a distance of about 10 km.
Other characteristics and advantages of the invention appear further from the following description. The description is purely illustrative and non-limiting. It should be read with reference to the accompanying figures, in which:
FIG. 1 is a diagram of a transmission system constituting a possible embodiment of the invention;
FIG. 2 is a graph plotting maps of cumulative dispersion in a prior art transmission system and in a transmission system constituting a possible embodiment of the invention.
The system shown in FIG. 1 has emitter means 1, receiver means 2, and an optical transmission line 3 which extends between said emitter and receiver means 1 and 2.
The emitter means 1 generate an optical signal constituted by a succession of RZ pulses. The receiver means demodulate the signal after it has been transmitted by the line 3.
This optical transmission line 3 includes a plurality of amplifiers 4 which are regularly distributed along its length.
Between successive amplifiers 4, the line has a plurality of fiber segments 3 a of anomalous dispersion alternating with fiber segments 3 b of normal dispersion.
These fiber segments 3 a and 3 b are such that for the majority of them (at least 90%), their cumulative dispersion C satisfies the relationship:
(R)|C|Δν2<0.3
where Δν is the half-height spectral width of the pulses (expressed in THz) and where C is the cumulative dispersion expressed in ps/nm.
This condition makes it possible to minimize interactions between pulses.
Preferably, the cumulative dispersion satisfies:
|C|Δν2<0.25
Thus, for a channel data rate of 20 Gbit/s, the cumulative dispersion is advantageously less than 150 ps/nm; for a channel data rate of 40 Gbit/s, the cumulative dispersion is advantageously less than 30 ps/nm.
Furthermore, the cumulative dispersion of the fiber segments also advantageously satisfies the relationship:
0.03<|C|Δν2
This condition makes it possible to reduce four-wave mixing and to reduce interaction between successive pulses.
Furthermore, by increasing the number of pairs of fiber segments 3 a, 3 b between successive amplifiers 4 it is possible to use fibers that are highly dispersive while remaining within a domain in which cumulative dispersion is small enough to minimize interactions between pulses. The anomalous fiber segments are advantageously selected to have chromatic dispersion greater than 8 ps/nm/km while the normal fiber segments are selected to have chromatic dispersion whose absolute value is greater than 8 ps/nm/km.
As an illustration, FIG. 2 is a map of the cumulative dispersion C1(z) (where z is distance) in a transmission system satisfying relationship R and having a single pair of fiber segments between successive amplifiers 4. FIG. 2 also shows a map of cumulative dispersion C2(z) (with local chromatic dispersion D1(z) being given by the slope of C1(z)) in a system, which for the same spacing between amplifiers 4 has two pairs of fiber segments between amplifiers, said transmission map satisfying C2(z)=2C1(z/2)
The second dispersion map makes it possible to use narrower pulses which interact less and which have smaller cross phase modulation effects than when using the first dispersion map.
This can be generalized to the case of a transmission map satisfying Cn(z)=nC1(z/n) and corresponding to a transmission system having n times as many dispersive segments between successive amplifiers (where n is an integer).
In FIG. 2, cumulative dispersion (in ps/nm) is represented by the dashed-line curves.
The anomalous fiber segments 3 a are advantageously constituted by single-mode fibers (SMF) of the kind used in standard manner in telecommunications.
SMF fibers are very dispersive.
They also present a large effective mode area—thus reducing non-linearity—low losses and small chromatic dispersion slopes.
The normal fiber segments 3 b are advantageously chromatic dispersion compensating fibers—referred to by the person skilled in the art as dispersion compensating fibers (DCF)—or reverse dispersion fibers (RDF), in which chromatic dispersion is substantially opposite to that of SMF fibers.
The distance between successive amplifiers 4 preferably lies in the range 35 km to 60 km.
The power level output by the amplifiers 4 is selected to be sufficient to enable a satisfactory signal-to-noise ratio to be achieved with low jitter.
The characteristics of the means 1 which constitute the emitter source (spectrum width, dispersive elements at line inlet, etc.) are defined by the chromatic dispersion map of the transmission line 3 and by the inline power of each channel. They are selected to obtain an operating point that is stable, enabling small variations in spectrum width to be accommodated during propagation.
The dispersion at the input to the receiver means 2 is optimized so as to minimize jitter and so as to re-time the signal.
To reduce the effects of cross phase modulation a little more:
1) guiding filtering can be used; and
2) overmodulation of chromatic dispersion having periodicity greater than the distance between amplifiers can be added: this is obtained by modifying the respective lengths of the dispersive segments.
A system of the type described above can be used to transmit a multiplex of N×20 Gbit/s (where N is an integer greater than or equal to 1, and can be as great as 40 or even more) over a transoceanic distance (>5000 km), together with line fibers constituted by standard fiber (SMF) which presents anomalous chromatic dispersion of about 17 ps/nm/km at a wavelength of 1550 nm, and a chromatic dispersion compensating fiber (DCF) which presents normal chromatic dispersion of about −85 ps/nm/km. Between successive amplifiers 4, the transmission line 3 is made up of three SMF type fiber segments 3 a each having a length equal to 8 km and three DCF type fiber segments 3 b alternating between the SMF segments and each presenting a length of 1.59 km, which corresponds to a distance between successive amplifiers that is approximately equal to 29 km.
The mean chromatic dispersion is anomalous (slightly less than 0.1 ps/nm/km). The power of the line amplifiers is −1.5 decibels relative to 1 milliwatt (mW) per channel (dBm/channel) which amounts to 10.5 dBm for 16 channels). Pulse duration is about 12 ps. The initial chromatic dispersion (typically −70 ps/nm) is optimized to obtain propagation that is stable. The high chromatic dispersion value makes it possible for channels to be spaced apart by 0.8 nm, or even by 0.6 nm.
The segments 3 b are advantageously made using DCF type fibers having a chromatic dispersion slope of about −0.26 ps/nm2/km. The chromatic dispersion slope of SMF fibers—which is about 0.053 ps/nm2/km—is then completely compensated. The transmission wavelength bandwidth is then limited only by the flatness of the amplifiers and can therefore exceed 25 nm.
In a variant, it is possible to use SMF fiber segments having chromatic dispersion of about 17 ps/nm/km at a wavelength of 1550 nm and RDF fiber segments having chromatic dispersion of opposite signs, i.e. chromatic dispersion of about −17 ps/nm/km. Between successive amplifiers 4, the transmission line 3 is constituted by two SMF type fiber segments 3 a each presenting a length of 8 km and two RDF type fiber segments 3 b alternating with the SMF segments and each presenting a length of 7.9 km, thus corresponding to a distance between successive amplifiers of approximately 32 km.
The mean chromatic dispersion is slightly less than 0.1 ps/nm/km. The power of the line amplifiers is 2 dBm/channel (i.e. 10 dBm for 16 channels). Pulse duration is about 13 ps. Channel spacing can be 0.8 nm or even 0.6 nm because of the high value of the chromatic dispersion. Furthermore, the RDF segments have a chromatic dispersion slope of about −0.05 ps/nm2/km which completely compensates the chromatic dispersion slope of the SMF segment (0.053 ps/nm2/km). The total bandwidth is thus limited by the flatness of the amplifiers and can therefore exceed 25 nm.
A total data rate in excess of 40×20 Gbit/s can be transmitted over a transoceanic distance.

Claims (13)

What is claimed is:
1. A long-distance optical transmission system comprising pulse emitter and receiver means and an optical line which extends between said emitter and receiver means and which comprises alternating segments of dispersive fibers having chromatic dispersion of opposite signs, and also having a plurality of amplifiers, said optical line comprising at least one pair of dispersive fiber segments having chromatic dispersion of opposite signs between successive amplifiers, the system being characterized in that said optical line comprises a plurality of such pairs between successive amplifiers, and in that the cumulative dispersion C over the majority of the segments of the optical line satisfies the relationship
|C|Δν2<0.3
where C is expressed in ps/nm and where Δν is the half-height spectral value of the pulses expressed in THz.
2. A system according to claim 1, characterized in that the cumulative dispersion C of the segments of the optical line satisfies the relationship:
|C|Δν2<0.25
where C is expressed in ps/nm and where Δν is expressed in THz.
3. A system according to claim 1, characterized in that the cumulative dispersion C of the segments of the optical line satisfies the relationship:
0.3<|C|Δν2
where C is expressed in ps/nm and where Aν is expressed in THz.
4. A system according to claim 3, characterized in that the chromatic dispersion of the segments of anomalous dispersion fiber is about 17 ps/nm/km at a wavelength of 1550 nm.
5. A system according to claim 4, characterized in that the chromatic dispersion of segments of normal dispersion fiber is about −85 ps/nm/km.
6. A system according to claim 5, characterized in that the optical line has three pairs of segments of dispersive fibers having chromatic dispersion of opposite signs, between successive amplifiers.
7. A system according to claim 6, characterized in that a segment of anomalous dispersion fiber extends over a distance of about 10 km and a segment of normal dispersion fiber extends over a distance of about 2 km.
8. A system according to claim 4, characterized in that the chromatic dispersion of the segments of normal dispersion fiber is about −17 ps/nm/km.
9. A system according to claim 8, characterized in that the optical line has two pairs of segments of dispersive fibers having chromatic dispersion of opposite signs between successive amplifiers.
10. A system according to claim 9, characterized in that a segment of fiber extends over a distance of about 10 km.
11. A system according to claim 9, characterized in that it includes guiding filtering means.
12. A system according to claim 1, characterized in that the respective lengths of the dispersive segments are selected so as to enable overmodulation of the chromatic dispersion.
13. A system according to claim 2, characterized in that the cumulative dispersion C of the segments of the optical line satisfies the relationship:
0.3<|C|Δν2
where C is expressed in ps/nm and where Δν is expressed in THz.
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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20040105685A1 (en) * 1997-07-31 2004-06-03 Btg International Limited Optical fibre communication system
US20040264900A1 (en) * 2001-02-02 2004-12-30 Sumitomo Electric Industries, Ltd. Optical fiber composite and optical fiber cable and production method thereof
US7352970B2 (en) * 1995-11-27 2008-04-01 Btg International Limited Dispersion management system for soliton optical transmission system

Families Citing this family (101)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6914717B1 (en) 1996-12-23 2005-07-05 Xtera Communications, Inc. Multiple wavelength pumping of raman amplifier stages
FR2773655B1 (en) * 1998-01-15 2000-02-11 Alsthom Cge Alcatel ELIMINATION OF THE LIMITATION OF OPTICAL POWER DUE TO THE RAMAN EFFECT IN FIBER OPTIC LINKS
US6597493B2 (en) 2000-05-05 2003-07-22 The Regents Of The University Of Michigan Nonlinear fiber amplifiers used for a 1430-1530nm low-loss window in optical fibers
JP3858451B2 (en) * 1998-06-03 2006-12-13 Kddi株式会社 Control signal superimposing device
US6574037B2 (en) 1998-06-16 2003-06-03 Xtera Communications, Inc. All band amplifier
US6344922B1 (en) * 1998-07-21 2002-02-05 Corvis Corporation Optical signal varying devices
EP1018666B1 (en) 1998-07-23 2012-04-18 The Furukawa Electric Co., Ltd. Optical repeater
US6567207B1 (en) 1999-05-12 2003-05-20 Corvis Corporation Optical transmission systems and optical amplifiers for use therein
US6587261B1 (en) * 1999-05-24 2003-07-01 Corvis Corporation Optical transmission systems including optical amplifiers and methods of use therein
DE60036353T2 (en) 1999-05-31 2008-06-05 The Furukawa Electric Co., Ltd. RAMAN GAIN METHOD
US6611370B2 (en) * 1999-07-23 2003-08-26 The Furukawa Electric Co., Ltd. Raman amplifier system, apparatus and method for identifying, obtaining and maintaining an arbitrary Raman amplification performance
US6611369B2 (en) * 1999-09-06 2003-08-26 Furukawa Electric Co., Ltd. Optical signal amplifier
FR2800218B1 (en) * 1999-10-22 2002-01-11 Algety Telecom FIBER OPTIC TRANSMISSION SYSTEM USING RZ PULSES
FR2800219B1 (en) * 1999-10-22 2006-06-30 Algety Telecom POWER ADJUSTMENT METHOD FOR WAVELENGTH MULTIPLEXING OPTICAL TRANSMISSION SYSTEM
US6407853B1 (en) * 1999-10-29 2002-06-18 Corning Incorporated Broadhead dual wavelength pumped fiber amplifier
US6583923B1 (en) * 1999-12-07 2003-06-24 Siemens Aktiengesellschaft Optical fiber amplifier
DE60139923D1 (en) * 2000-01-12 2009-10-29 Xtera Comm Inc TWO-SIDED PUMP RAMA AMPLIFIER
EP2755289A3 (en) * 2000-01-14 2015-01-21 The Furukawa Electric Co., Ltd. WDM, multiple wavelength pumped, Raman amplifier
JP2001249369A (en) * 2000-03-02 2001-09-14 Nec Corp Optical amplifier and optical amplification repeater using the same, and wavelength multiplex transmission device
US6344925B1 (en) 2000-03-03 2002-02-05 Corvis Corporation Optical systems and methods and optical amplifiers for use therein
US6384963B2 (en) * 2000-03-03 2002-05-07 Lucent Technologies Inc. Optical communication system with co-propagating pump radiation for raman amplification
US20040130778A1 (en) * 2003-01-06 2004-07-08 Corvis Corporation Optical transmission systems including optical amplifiers and methods of use therein
JP2002040495A (en) * 2000-07-21 2002-02-06 Sumitomo Electric Ind Ltd Raman amplifier
US6426833B1 (en) * 2000-07-28 2002-07-30 Ciena Corporation Optical amplifier configuration including shared pumps
US6700696B2 (en) 2000-08-09 2004-03-02 Jds Uniphase Corporation High order fiber Raman amplifiers
US6657774B1 (en) * 2000-08-18 2003-12-02 Corning Incorporated Amplifier system with distributed and discrete Raman fiber amplifiers
JP4821037B2 (en) * 2000-08-25 2011-11-24 富士通株式会社 Optical amplifier and Raman pump light source using Raman amplification
US6452715B1 (en) 2000-08-29 2002-09-17 Ciena Corporation Method and apparatus for determining a fiber plant gain transfer function and utilizing same to control distributed gain
JP2002076482A (en) * 2000-08-31 2002-03-15 Fujitsu Ltd Optical amplifier, optical amplification method and optical amplification system
DE10048460B4 (en) * 2000-09-29 2004-02-12 Siemens Ag Raman amplifier
US6782199B1 (en) 2000-09-29 2004-08-24 Onetta, Inc. Optical communications systems with optical subsystem communications links
US6424457B1 (en) 2000-10-06 2002-07-23 Onetta, Inc. Optical amplifiers and methods for manufacturing optical amplifiers
US6504989B1 (en) 2000-10-23 2003-01-07 Onetta, Inc. Optical equipment and methods for manufacturing optical communications equipment for networks
US6498677B1 (en) 2000-10-23 2002-12-24 Onetta, Inc. Optical amplifier systems with transient control
US6441950B1 (en) 2000-11-03 2002-08-27 Onetta, Inc. Distributed raman amplifier systems with transient control
DE10057659B4 (en) 2000-11-21 2004-01-15 Siemens Ag Optical transmission system with cascaded Raman amplifiers each having several pump sources
US6417959B1 (en) 2000-12-04 2002-07-09 Onetta, Inc. Raman fiber amplifier
US6542287B1 (en) * 2000-12-12 2003-04-01 Onetta, Inc. Optical amplifier systems with transient control
US6396623B1 (en) 2000-12-19 2002-05-28 Onetta, Inc. Wide-band optical amplifiers with interleaved gain stages
US6625347B1 (en) 2001-01-12 2003-09-23 Onetta, Inc. Pumps for Raman amplifier systems
US6433921B1 (en) 2001-01-12 2002-08-13 Onetta, Inc. Multiwavelength pumps for raman amplifier systems
JP2002229083A (en) * 2001-01-31 2002-08-14 Sumitomo Electric Ind Ltd Optical communication system
EP1229675A3 (en) * 2001-02-02 2004-09-22 The Furukawa Electric Co., Ltd. Pump light source for raman amplifier and raman amplifier using the same
US6633430B1 (en) 2001-02-15 2003-10-14 Onetta, Inc. Booster amplifier with spectral control for optical communications systems
US6417965B1 (en) 2001-02-16 2002-07-09 Onetta, Inc. Optical amplifier control system
US6522459B1 (en) 2001-02-22 2003-02-18 Onetta, Inc. Temperature control and monitoring of optical detector components in an optical communication system
US6507430B2 (en) 2001-02-23 2003-01-14 Photon X, Inc. Long wavelength optical amplifier
US6731426B2 (en) 2001-02-23 2004-05-04 Photon-X, Inc. Long wavelength optical amplifier
US6636345B2 (en) * 2001-02-27 2003-10-21 Corning Incorporated Optical fiber pumping system
US6438010B1 (en) 2001-03-02 2002-08-20 Onetta, Inc. Drive circuits for microelectromechanical systems devices
US6624927B1 (en) 2001-03-14 2003-09-23 Onetta, Inc. Raman optical amplifiers
US6731424B1 (en) 2001-03-15 2004-05-04 Onetta, Inc. Dynamic gain flattening in an optical communication system
US6532101B2 (en) 2001-03-16 2003-03-11 Xtera Communications, Inc. System and method for wide band Raman amplification
US6810214B2 (en) 2001-03-16 2004-10-26 Xtera Communications, Inc. Method and system for reducing degradation of optical signal to noise ratio
US7027155B2 (en) * 2001-03-29 2006-04-11 Gsi Lumonics Corporation Methods and systems for precisely relatively positioning a waist of a pulsed laser beam and method and system for controlling energy delivered to a target structure
JP4188573B2 (en) 2001-04-09 2008-11-26 株式会社日立製作所 Optical amplifier amplification band expansion method, optical amplifier, and extension unit
US6850360B1 (en) 2001-04-16 2005-02-01 Bookham, Inc. Raman amplifier systems with diagnostic capabilities
US6606337B1 (en) * 2001-04-26 2003-08-12 Jds Uniphase Corp. Multiple band Raman amplifier pump source
US6529316B1 (en) 2001-05-03 2003-03-04 Onetta, Inc. Optical network equipment with optical channel monitor and dynamic spectral filter alarms
US6545800B1 (en) 2001-06-05 2003-04-08 Onetta, Inc. Depolarizers for optical channel monitors
US6483631B1 (en) 2001-06-05 2002-11-19 Onetta, Inc. Optical amplifier spectral tilt controllers
US6621621B1 (en) 2001-06-07 2003-09-16 Innovance, Inc. Line amplification system for wavelength switched optical networks
US20040100684A1 (en) * 2001-06-07 2004-05-27 Jones Kevan Peter Line amplification system for wavelength switched optical networks
US6556345B1 (en) 2001-06-21 2003-04-29 Onetta, Inc. Optical network equipment with control and data paths
US6456426B1 (en) 2001-06-28 2002-09-24 Onetta, Inc. Raman amplifiers with modulated pumps
US6687049B1 (en) 2001-07-03 2004-02-03 Onetta, Inc. Optical amplifiers with stable output power under low input power conditions
US6525870B1 (en) 2001-07-26 2003-02-25 Ciena Corporation Method and system for controlling Raman gain flatness sensitivity to pump laser wavelength variation
US6587259B2 (en) 2001-07-27 2003-07-01 Xtera Communications, Inc. System and method for controlling noise figure
JPWO2003016996A1 (en) * 2001-08-21 2004-12-09 古河電気工業株式会社 Raman amplification method
US6577789B1 (en) 2001-09-26 2003-06-10 Onetta, Inc. Double-pass optical amplifiers and optical network equipment
US6781748B2 (en) 2001-09-28 2004-08-24 Photon-X, Llc Long wavelength optical amplifier
US6594071B1 (en) 2001-10-02 2003-07-15 Xtera Communications, Inc. Method and apparatus for amplifier control
US20030077032A1 (en) * 2001-10-10 2003-04-24 Duling Irl N. Long distance optical transmission system for high dynamic range signals
US20030151799A1 (en) * 2001-10-11 2003-08-14 Innovance, Inc. Gain control in wavelength switched optical networks
AU2002366169A1 (en) * 2001-11-19 2003-06-10 Photon-X, Inc. L band optical amplifier
US6731428B2 (en) 2001-11-21 2004-05-04 Lucent Technologies Inc. Pump monitoring and control in a fiber Raman amplifier
US6914716B2 (en) * 2001-11-21 2005-07-05 Lucent Technologies Inc. Modulated pump source for fiber Raman amplifier
US6657776B2 (en) 2001-11-21 2003-12-02 Lucent Technologies Inc. Pump source including polarization scrambling in Raman amplified optical WDM systems
EP1322005A1 (en) * 2001-12-19 2003-06-25 University Of Southampton Sources and methods of generating optical radiation
WO2003052884A2 (en) * 2001-12-19 2003-06-26 University Of Southampton Sources of, and methods of generating, optical radiation
US6819479B1 (en) 2001-12-20 2004-11-16 Xtera Communications, Inc. Optical amplification using launched signal powers selected as a function of a noise figure
JP4007812B2 (en) * 2002-01-18 2007-11-14 富士通株式会社 Raman amplifier, wavelength division multiplexing optical communication system, and control method of Raman amplification
JP4082049B2 (en) * 2002-03-12 2008-04-30 富士通株式会社 Optical transmitter
US6819478B1 (en) 2002-03-15 2004-11-16 Xtera Communications, Inc. Fiber optic transmission system with low cost transmitter compensation
US6768577B2 (en) 2002-03-15 2004-07-27 Fitel Usa Corp. Tunable multimode laser diode module, tunable multimode wavelength division multiplex raman pump, and amplifier, and a system, method, and computer program product for controlling tunable multimode laser diodes, raman pumps, and raman amplifiers
US7199919B2 (en) * 2002-03-15 2007-04-03 The Furukawa Electric Co., Ltd. Tunable multimode wavelength division multiplex Raman pump and amplifier, and a system, method, and computer program product for controlling tunable Raman pumps, and Raman amplifiers
US6778321B1 (en) 2002-03-15 2004-08-17 Xtera Communications, Inc. Fiber optic transmission system for a metropolitan area network
US7197245B1 (en) 2002-03-15 2007-03-27 Xtera Communications, Inc. System and method for managing system margin
US20040208586A1 (en) * 2002-03-27 2004-10-21 Susumu Kinoshita System and method for amplifying signals in an optical network
AU2003230897A1 (en) * 2002-04-12 2003-10-27 Corvis Corporation Optical communication systems including optical amplifiers and amplification methods
JP2004086143A (en) * 2002-06-28 2004-03-18 Sumitomo Electric Ind Ltd Light transmission system
ATE287159T1 (en) * 2002-07-11 2005-01-15 Cit Alcatel DEMULTIPLEXER FOR OPTICAL TIME MULTIPLEXED SIGNALS
US6879434B2 (en) * 2002-07-11 2005-04-12 Fujitsu Network Communications, Inc. Distributed raman amplifier for optical network and method
JP2004080301A (en) * 2002-08-15 2004-03-11 Kddi Submarine Cable Systems Inc Method and system for monitoring distributed raman optical transmission line
US20040070819A1 (en) * 2002-10-11 2004-04-15 Nortel Networks Limited Broadband tunable optical amplifier
JP4532407B2 (en) * 2003-02-27 2010-08-25 古河電気工業株式会社 Wavelength multiplexing excitation Raman amplifier control apparatus, wavelength multiplexing excitation Raman amplifier, and control method therefor
US6998783B2 (en) * 2003-03-03 2006-02-14 L-3 Communications Corporation Inductive output tube having a broadband impedance circuit
JP4558425B2 (en) * 2003-09-08 2010-10-06 古河電気工業株式会社 Raman amplifier, excitation source for use in Raman amplifier, method for amplifying optical signal
US7522334B2 (en) * 2004-02-19 2009-04-21 Corvis Equipment Corporation Optical communication systems including optical amplifiers and amplification methods with flat noise figure profile
JP5838748B2 (en) * 2011-11-15 2016-01-06 富士通株式会社 Optical transmission system, pumping light supply control method, and pumping light supply apparatus
JP6774753B2 (en) * 2015-05-13 2020-10-28 古河電気工業株式会社 Raman amplification light source system, Raman amplifier, Raman amplification system

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0575881A1 (en) 1992-06-22 1993-12-29 Nec Corporation Optical communication transmission system with chromatic dispersion compensation
US5559910A (en) 1994-06-06 1996-09-24 Kokusai Denshin Denwa Kabushiki Kaisha Wavelength division multiplexed optical fiber transmission equiptment
GB2299473A (en) 1995-03-27 1996-10-02 Hitachi Cable Broadband long-distance optical fibre communications
US5611016A (en) * 1996-06-07 1997-03-11 Lucent Technologies Inc. Dispersion-balanced optical cable
FR2757720A1 (en) 1996-12-19 1998-06-26 Alsthom Cge Alcatel Optical terminal adaptor manufacturing method
US5940208A (en) * 1996-04-02 1999-08-17 Corning Incorporated Switchable fiber optic device for fiber transmission system and components thereof
US6173588B1 (en) * 1996-01-11 2001-01-16 Corning Incorporated Method of making dispersion managed optical fibers
US6229935B1 (en) * 1995-12-21 2001-05-08 Alcatel Dispersion slope compensation in optical transmission systems
US6292603B1 (en) * 1998-05-29 2001-09-18 Kokusai Denshin Denwa Co., Ltd. Dispersion compensation device

Family Cites Families (34)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4342499A (en) * 1979-03-19 1982-08-03 Hicks Jr John W Communications tuning construction
US4315666A (en) * 1979-03-19 1982-02-16 Hicks Jr John W Coupled communications fibers
US4616898A (en) * 1980-03-31 1986-10-14 Polaroid Corporation Optical communication systems using raman repeaters and components therefor
JPS56165437A (en) * 1980-05-26 1981-12-19 Kokusai Denshin Denwa Co Ltd <Kdd> Optical repeating system for optical communication
GB2158603B (en) * 1984-05-11 1987-07-29 Stc Plc Single mode optical fibre attenuators
US4699452A (en) * 1985-10-28 1987-10-13 American Telephone And Telegraph Company, At&T Bell Laboratories Optical communications system comprising Raman amplification means
JPH0727149B2 (en) * 1986-11-04 1995-03-29 沖電気工業株式会社 Optical coupler
US5228105A (en) 1987-05-04 1993-07-13 Glista Andrew S Programmable electro-optic packaging and interconnect system
US4881790A (en) * 1988-04-25 1989-11-21 American Telephone And Telegraph Company, At&T Bell Laboratories Optical communications system comprising raman amplification means
US5083874A (en) * 1989-04-14 1992-01-28 Nippon Telegraph And Telephone Corporation Optical repeater and optical network using the same
US5039199A (en) * 1989-12-29 1991-08-13 At&T Bell Laboratories Lightwave transmission system having remotely pumped quasi-distributed amplifying fibers
GB2249682B (en) 1990-11-09 1995-03-29 Stc Plc Optical amplifiers
US5095519A (en) * 1990-11-30 1992-03-10 At&T Bell Laboratories Apparatus and method for producing an in-line optical fiber attenuator
US5579143A (en) * 1993-06-04 1996-11-26 Ciena Corporation Optical system with tunable in-fiber gratings
US5406411A (en) * 1993-10-14 1995-04-11 Corning Incorporated Fiber amplifier having efficient pump power utilization
JP2734969B2 (en) 1993-12-29 1998-04-02 日本電気株式会社 Optical fiber amplifier for WDM transmission
GB9411061D0 (en) * 1994-06-02 1994-07-20 Northern Telecom Ltd Optical waveguide amplifiers
US5651085A (en) * 1994-09-27 1997-07-22 Chia; Shin-Lo All fiber attenuator
US5633974A (en) * 1994-09-27 1997-05-27 The Whitaker Corporation All fiber attenuator
US5541766A (en) * 1994-11-30 1996-07-30 At&T Corp. Gain control for optically amplified systems
JPH08248455A (en) * 1995-03-09 1996-09-27 Fujitsu Ltd Optical amplifier for wavelength multiplexing
EP1841022A3 (en) * 1995-03-20 2009-12-02 Fujitsu Limited Apparatus and method for processing an optical signal
US5696615A (en) * 1995-11-13 1997-12-09 Ciena Corporation Wavelength division multiplexed optical communication systems employing uniform gain optical amplifiers
JP3403288B2 (en) * 1996-02-23 2003-05-06 古河電気工業株式会社 Optical amplifier
US5694512A (en) * 1996-07-09 1997-12-02 Framatome Connectors Canada Inc. Compact tunable wavelength independent all-fiber optical attenuator and method of making same
JPH10130055A (en) * 1996-10-24 1998-05-19 Tokyo Electron Ltd Production of electrode plate for plasma treatment device
US6122298A (en) 1996-11-01 2000-09-19 Tyco Submarine Systems Ltd. Multi-wavelength optical pump
DE69815314T2 (en) * 1997-03-17 2003-12-11 Jds Uniphase Corp MULTI-STAGE FIBER OPTICAL AMPLIFIER
EP0883217B1 (en) * 1997-06-06 2003-10-29 Corning Photonic Technologies Inc. Optical fiber telecommunication system
US5999548A (en) * 1997-06-18 1999-12-07 Nippon Telegraph And Telephone Corporation White optical pulse source and applications
US6081366A (en) * 1997-08-28 2000-06-27 Lucent Technologies Inc. Optical fiber communication system with a distributed Raman amplifier and a remotely pumped er-doped fiber amplifier
US5920423A (en) 1997-12-05 1999-07-06 Sdl, Inc. Multiple pumped fiber amplifiers for WDM communication systems with adjustment for the amplifier signal gain bandwidth
US6057959A (en) 1998-05-22 2000-05-02 Ciena Corporation Optical amplifier having substantially uniform spectral gain
US5963361A (en) 1998-05-22 1999-10-05 Ciena Corporation Optical amplifier having a variable attenuator controlled based on detected ASE

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0575881A1 (en) 1992-06-22 1993-12-29 Nec Corporation Optical communication transmission system with chromatic dispersion compensation
US5559910A (en) 1994-06-06 1996-09-24 Kokusai Denshin Denwa Kabushiki Kaisha Wavelength division multiplexed optical fiber transmission equiptment
GB2299473A (en) 1995-03-27 1996-10-02 Hitachi Cable Broadband long-distance optical fibre communications
US6229935B1 (en) * 1995-12-21 2001-05-08 Alcatel Dispersion slope compensation in optical transmission systems
US6173588B1 (en) * 1996-01-11 2001-01-16 Corning Incorporated Method of making dispersion managed optical fibers
US5940208A (en) * 1996-04-02 1999-08-17 Corning Incorporated Switchable fiber optic device for fiber transmission system and components thereof
US5611016A (en) * 1996-06-07 1997-03-11 Lucent Technologies Inc. Dispersion-balanced optical cable
FR2757720A1 (en) 1996-12-19 1998-06-26 Alsthom Cge Alcatel Optical terminal adaptor manufacturing method
US6292603B1 (en) * 1998-05-29 2001-09-18 Kokusai Denshin Denwa Co., Ltd. Dispersion compensation device

Non-Patent Citations (6)

* Cited by examiner, † Cited by third party
Title
Edagawa, N., Morita, I., Suzuki, M., Yamamoto, S., Tanaka, K. and Akiba, S., "Long distance soliton WDM transmission using a dispersion-flattened fiber", OFC' 97, Post deadline paper, pp. PD19-1-PD19-4, Dallas, Texas, USA.
Le Guen, D., O'Hare, A., Del Burgo, S., Grot, D., Favre, F. and Georges, T., "Narrow band 640 Gbit/s soliton WDM transmission over 1200km of standard fiber with 100km-21db amplifier spans", ECOC'98, Sep. 20-24, 1998, Post deadline paper, pp. 61&63, Madrid, Spain.
Morita, I., Tanaka, K. Edagawa, N. and Suzuki, M., "40 Gbit/s single-channel soliton transmission over 10,200 km without active inline transmission control", ECOC' 98, Sep. 20-24, 1998, Post deadline paper pp. 49&51, Madrid, Spain.
Murakami, M., Matsuda, T. and Imai, T., "Quarter Terabit (25x10 Gbit/s) over 9288km WDM, transmission experiment using non-linear supported RZ pulse in higher order fiber dispersion managed line" , ECOC' 98, Sep. 20-24, 1998, Post deadline paper, pp. 79&81, Madrid, Spain.
Suzuki, M., et al., "170 Gbit/s transmission over 10,850 km using large core tranmission fiber", OFC' 98, Post deadline paper, pp. PD17-1-PD17-4, San Jose, California, USA.
Taga, H., Edagawa, N., Suzuki, M., Takeda, N., Imai, K., Yamamoto, S. and Akiba, S., "213 Gbit/s (20x10.66) over 9000km transmission experiment using dispersion-slope compensator", OFC' 98, Post deadline paper, pp. PD13-1 -PD-13-4, San Jose, California, USA.

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7352970B2 (en) * 1995-11-27 2008-04-01 Btg International Limited Dispersion management system for soliton optical transmission system
US20090087190A1 (en) * 1995-11-27 2009-04-02 Nicholas John Doran Optical communications
US20040105685A1 (en) * 1997-07-31 2004-06-03 Btg International Limited Optical fibre communication system
US20040264900A1 (en) * 2001-02-02 2004-12-30 Sumitomo Electric Industries, Ltd. Optical fiber composite and optical fiber cable and production method thereof
US6907171B2 (en) * 2001-02-02 2005-06-14 Sumitomo Electric Industries, Ltd. Optical fiber composite and optical fiber cable and production method thereof

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